<template>
	<view class="container">
		<view class="page-body uni-content-info">
			<view class='cropper-content'>
				<view v-if="isShowImg" class="uni-corpper" :style="'width:'+cropperInitW+'px;height:'+cropperInitH+'px;background:#000'">
					<view class="uni-corpper-content" :style="'width:'+cropperW+'px;height:'+cropperH+'px;left:'+cropperL+'px;top:'+cropperT+'px'">
						<image :src="imageSrc" :style="'width:'+cropperW+'px;height:'+cropperH+'px'"></image>
						<view class="uni-corpper-crop-box" @touchstart.stop="contentStartMove" @touchmove.stop="contentMoveing" @touchend.stop="contentTouchEnd"
						    :style="'left:'+cutL+'px;top:'+cutT+'px;right:'+cutR+'px;bottom:'+cutB+'px'">
							<view class="uni-cropper-view-box">
								<view class="uni-cropper-dashed-h"></view>
								<view class="uni-cropper-dashed-v"></view>
								<view class="uni-cropper-line-t" data-drag="top" @touchstart.stop="dragStart" @touchmove.stop="dragMove"></view>
								<view class="uni-cropper-line-r" data-drag="right" @touchstart.stop="dragStart" @touchmove.stop="dragMove"></view>
								<view class="uni-cropper-line-b" data-drag="bottom" @touchstart.stop="dragStart" @touchmove.stop="dragMove"></view>
								<view class="uni-cropper-line-l" data-drag="left" @touchstart.stop="dragStart" @touchmove.stop="dragMove"></view>
								<view class="uni-cropper-point point-t" data-drag="top" @touchstart.stop="dragStart" @touchmove.stop="dragMove"></view>
								<view class="uni-cropper-point point-tr" data-drag="topTight"></view>
								<view class="uni-cropper-point point-r" data-drag="right" @touchstart.stop="dragStart" @touchmove.stop="dragMove"></view>
								<view class="uni-cropper-point point-rb" data-drag="rightBottom" @touchstart.stop="dragStart" @touchmove.stop="dragMove"></view>
								<view class="uni-cropper-point point-b" data-drag="bottom" @touchstart.stop="dragStart" @touchmove.stop="dragMove" @touchend.stop="dragEnd"></view>
								<view class="uni-cropper-point point-bl" data-drag="bottomLeft"></view>
								<view class="uni-cropper-point point-l" data-drag="left" @touchstart.stop="dragStart" @touchmove.stop="dragMove"></view>
								<view class="uni-cropper-point point-lt" data-drag="leftTop"></view>
							</view>
						</view>
					</view>
				</view>
			</view>
			<view class='cropper-config'>
				<button type="primary reverse" @click="getImage" style='margin-top: 30rpx;'> 选择头像 </button>
				<button v-if="showSubmit" type="warn" @click="getImageInfo" style='margin-top: 30rpx;'> 提交 </button>
			</view>
			<canvas canvas-id="myCanvas" :style="'position:absolute;border: 1px solid red; width:'+imageW+'px;height:'+imageH+'px;top:-9999px;left:-9999px;'"></canvas>
		</view>
	</view>
</template>

<script>
	import global from '@/global'
	import {useUserStore} from "@/store";
	import {uploadAvatar} from "@/api/system/user";
	
	const userStore = useUserStore();
	
	const baseUrl = global.baseUrl
		let sysInfo = uni.getSystemInfoSync()
		let SCREEN_WIDTH = sysInfo.screenWidth
		let PAGE_X, // 手按下的x位置
			PAGE_Y, // 手按下y的位置 
			PR = sysInfo.pixelRatio, // dpi
			T_PAGE_X, // 手移动的时候x的位置
			T_PAGE_Y, // 手移动的时候Y的位置
			CUT_L, // 初始化拖拽元素的left值
			CUT_T, // 初始化拖拽元素的top值
			CUT_R, // 初始化拖拽元素的
			CUT_B, // 初始化拖拽元素的
			CUT_W, // 初始化拖拽元素的宽度
			CUT_H, //  初始化拖拽元素的高度
			IMG_RATIO, // 图片比例
			IMG_REAL_W, // 图片实际的宽度
			IMG_REAL_H, // 图片实际的高度
			DRAFG_MOVE_RATIO = 1, //移动时候的比例,
			INIT_DRAG_POSITION = 100, // 初始化屏幕宽度和裁剪区域的宽度之差，用于设置初始化裁剪的宽度
			DRAW_IMAGE_W = sysInfo.screenWidth // 设置生成的图片宽度
	
		export default {
			/**
			 * 页面的初始数据
			 */
			data() {
				return {
					showSubmit: false,
					imageSrc: userStore.avatar,
					isShowImg: false,
					// 初始化的宽高
					cropperInitW: SCREEN_WIDTH,
					cropperInitH: SCREEN_WIDTH,
					// 动态的宽高
					cropperW: SCREEN_WIDTH,
					cropperH: SCREEN_WIDTH,
					// 动态的left top值
					cropperL: 0,
					cropperT: 0,
	
					transL: 0,
					transT: 0,
	
					// 图片缩放值
					scaleP: 0,
					imageW: 0,
					imageH: 0,
	
					// 裁剪框 宽高
					cutL: 0,
					cutT: 0,
					cutB: SCREEN_WIDTH,
					cutR: '100%',
					qualityWidth: DRAW_IMAGE_W,
					innerAspectRadio: DRAFG_MOVE_RATIO
				}
			},
			/**
			 * 生命周期函数--监听页面初次渲染完成
			 */
			onReady: function () {
				this.loadImage()
			},
			methods: {
				setData: function (obj) {
					let that = this
					Object.keys(obj).forEach(function (key) {
						that.$set(that.$data, key, obj[key])
					})
				},
				getImage: function () {
					var _this = this
					uni.chooseImage({
						success: function (res) {
							_this.setData({
								imageSrc: res.tempFilePaths[0],
							})
							_this.loadImage()
							_this.showSubmit = true
						},
					})
				},
				loadImage: function () {
					var _this = this
	
					uni.getImageInfo({
						src: _this.imageSrc,
						success: function success(res) {
							IMG_RATIO = 1 / 1
							if (IMG_RATIO >= 1) {
								IMG_REAL_W = SCREEN_WIDTH
								IMG_REAL_H = SCREEN_WIDTH / IMG_RATIO
							} else {
								IMG_REAL_W = SCREEN_WIDTH * IMG_RATIO
								IMG_REAL_H = SCREEN_WIDTH
							}
							let minRange = IMG_REAL_W > IMG_REAL_H ? IMG_REAL_W : IMG_REAL_H
							INIT_DRAG_POSITION = minRange > INIT_DRAG_POSITION ? INIT_DRAG_POSITION : minRange
							// 根据图片的宽高显示不同的效果   保证图片可以正常显示
							if (IMG_RATIO >= 1) {
								let cutT = Math.ceil((SCREEN_WIDTH / IMG_RATIO - (SCREEN_WIDTH / IMG_RATIO - INIT_DRAG_POSITION)) / 2)
								let cutB = cutT
								let cutL = Math.ceil((SCREEN_WIDTH - SCREEN_WIDTH + INIT_DRAG_POSITION) / 2)
								let cutR = cutL
								_this.setData({
									cropperW: SCREEN_WIDTH,
									cropperH: SCREEN_WIDTH / IMG_RATIO,
									// 初始化left right
									cropperL: Math.ceil((SCREEN_WIDTH - SCREEN_WIDTH) / 2),
									cropperT: Math.ceil((SCREEN_WIDTH - SCREEN_WIDTH / IMG_RATIO) / 2),
									cutL: cutL,
									cutT: cutT,
									cutR: cutR,
									cutB: cutB,
									// 图片缩放值
									imageW: IMG_REAL_W,
									imageH: IMG_REAL_H,
									scaleP: IMG_REAL_W / SCREEN_WIDTH,
									qualityWidth: DRAW_IMAGE_W,
									innerAspectRadio: IMG_RATIO
								})
							} else {
								let cutL = Math.ceil((SCREEN_WIDTH * IMG_RATIO - (SCREEN_WIDTH * IMG_RATIO)) / 2)
								let cutR = cutL
								let cutT = Math.ceil((SCREEN_WIDTH - INIT_DRAG_POSITION) / 2)
								let cutB = cutT
								_this.setData({
									cropperW: SCREEN_WIDTH * IMG_RATIO,
									cropperH: SCREEN_WIDTH,
									// 初始化left right
									cropperL: Math.ceil((SCREEN_WIDTH - SCREEN_WIDTH * IMG_RATIO) / 2),
									cropperT: Math.ceil((SCREEN_WIDTH - SCREEN_WIDTH) / 2),
	
									cutL: cutL,
									cutT: cutT,
									cutR: cutR,
									cutB: cutB,
									// 图片缩放值
									imageW: IMG_REAL_W,
									imageH: IMG_REAL_H,
									scaleP: IMG_REAL_W / SCREEN_WIDTH,
									qualityWidth: DRAW_IMAGE_W,
									innerAspectRadio: IMG_RATIO
								})
							}
							_this.setData({
								isShowImg: true
							})
							uni.hideLoading()
						}
					})
				},
				// 拖动时候触发的touchStart事件
				contentStartMove(e) {
					PAGE_X = e.touches[0].pageX
					PAGE_Y = e.touches[0].pageY
				},
	
				// 拖动时候触发的touchMove事件
				contentMoveing(e) {
					var _this = this
					var dragLengthX = (PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO
					var dragLengthY = (PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO
					// 左移
					if (dragLengthX > 0) {
						if (this.cutL - dragLengthX < 0) dragLengthX = this.cutL
					} else {
						if (this.cutR + dragLengthX < 0) dragLengthX = -this.cutR
					}
	
					if (dragLengthY > 0) {
						if (this.cutT - dragLengthY < 0) dragLengthY = this.cutT
					} else {
						if (this.cutB + dragLengthY < 0) dragLengthY = -this.cutB
					}
					this.setData({
						cutL: this.cutL - dragLengthX,
						cutT: this.cutT - dragLengthY,
						cutR: this.cutR + dragLengthX,
						cutB: this.cutB + dragLengthY
					})
	
					PAGE_X = e.touches[0].pageX
					PAGE_Y = e.touches[0].pageY
				},
	
				contentTouchEnd() {
	
				},
	
				// 获取图片
				getImageInfo() {
					var _this = this
					uni.showLoading({
						title: '图片生成中...',
					})
					// 将图片写入画布
					const ctx = uni.createCanvasContext('myCanvas')
					ctx.drawImage(_this.imageSrc, 0, 0, IMG_REAL_W, IMG_REAL_H)
					ctx.draw(true, () => {
						// 获取画布要裁剪的位置和宽度   均为百分比 * 画布中图片的宽度    保证了在微信小程序中裁剪的图片模糊  位置不对的问题 canvasT = (_this.cutT / _this.cropperH) * (_this.imageH / pixelRatio)
						var canvasW = ((_this.cropperW - _this.cutL - _this.cutR) / _this.cropperW) * IMG_REAL_W
						var canvasH = ((_this.cropperH - _this.cutT - _this.cutB) / _this.cropperH) * IMG_REAL_H
						var canvasL = (_this.cutL / _this.cropperW) * IMG_REAL_W
						var canvasT = (_this.cutT / _this.cropperH) * IMG_REAL_H
						uni.canvasToTempFilePath({
							x: canvasL,
							y: canvasT,
							width: canvasW,
							height: canvasH,
							destWidth: canvasW,
							destHeight: canvasH,
							quality: 0.5,
							canvasId: 'myCanvas',
							success: function (res) {
								uni.hideLoading()
								let data = {name: 'avatarFile', filePath: res.tempFilePath}
								uploadAvatar(data).then(response => {
									userStore.avatar = baseUrl + response.data;
									uni.showToast({ title: "修改成功", icon: 'success' })
									uni.navigateBack()
								})
							}
						})
					})
				},
				// 设置大小的时候触发的touchStart事件
				dragStart(e) {
					T_PAGE_X = e.touches[0].pageX
					T_PAGE_Y = e.touches[0].pageY
					CUT_L = this.cutL
					CUT_R = this.cutR
					CUT_B = this.cutB
					CUT_T = this.cutT
				},
	
				// 设置大小的时候触发的touchMove事件
				dragMove(e) {
					var _this = this
					var dragType = e.target.dataset.drag
					switch (dragType) {
						case 'right':
							var dragLength = (T_PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO
							if (CUT_R + dragLength < 0) dragLength = -CUT_R
							this.setData({
								cutR: CUT_R + dragLength
							})
							break
						case 'left':
							var dragLength = (T_PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO
							if (CUT_L - dragLength < 0) dragLength = CUT_L
							if ((CUT_L - dragLength) > (this.cropperW - this.cutR)) dragLength = CUT_L - (this.cropperW - this.cutR)
							this.setData({
								cutL: CUT_L - dragLength
							})
							break
						case 'top':
							var dragLength = (T_PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO
							if (CUT_T - dragLength < 0) dragLength = CUT_T
							if ((CUT_T - dragLength) > (this.cropperH - this.cutB)) dragLength = CUT_T - (this.cropperH - this.cutB)
							this.setData({
								cutT: CUT_T - dragLength
							})
							break
						case 'bottom':
							var dragLength = (T_PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO
							if (CUT_B + dragLength < 0) dragLength = -CUT_B
							this.setData({
								cutB: CUT_B + dragLength
							})
							break
						case 'rightBottom':
							var dragLengthX = (T_PAGE_X - e.touches[0].pageX) * DRAFG_MOVE_RATIO
							var dragLengthY = (T_PAGE_Y - e.touches[0].pageY) * DRAFG_MOVE_RATIO
	
							if (CUT_B + dragLengthY < 0) dragLengthY = -CUT_B
							if (CUT_R + dragLengthX < 0) dragLengthX = -CUT_R
							let cutB = CUT_B + dragLengthY
							let cutR = CUT_R + dragLengthX
	
							this.setData({
								cutB: cutB,
								cutR: cutR
							})
							break
						default:
							break
					}
				}
			}
		}
</script>

<style>
	.cropper-config {
		padding: 20rpx 40rpx;
	}
	
	.cropper-content {
		min-height: 750rpx;
		width: 100%;
	}
	
	.uni-corpper {
		position: relative;
		overflow: hidden;
		-webkit-user-select: none;
		-moz-user-select: none;
		-ms-user-select: none;
		user-select: none;
		-webkit-tap-highlight-color: transparent;
		-webkit-touch-callout: none;
		box-sizing: border-box;
	}
	
	.uni-corpper-content {
		position: relative;
	}
	
	.uni-corpper-content image {
		display: block;
		width: 100%;
		min-width: 0 !important;
		max-width: none !important;
		height: 100%;
		min-height: 0 !important;
		max-height: none !important;
		image-orientation: 0deg !important;
		margin: 0 auto;
	}
	/* 移动图片效果 */
	
	.uni-cropper-drag-box {
		position: absolute;
		top: 0;
		right: 0;
		bottom: 0;
		left: 0;
		cursor: move;
		background: rgba(0, 0, 0, 0.6);
		z-index: 1;
	}
	/* 内部的信息 */
	
	.uni-corpper-crop-box {
		position: absolute;
		background: rgba(255, 255, 255, 0.3);
		z-index: 2;
	}
	
	.uni-corpper-crop-box .uni-cropper-view-box {
		position: relative;
		display: block;
		width: 100%;
		height: 100%;
		overflow: visible;
		outline: 1rpx solid #69f;
		outline-color: rgba(102, 153, 255, .75)
	}
	/* 横向虚线 */
	
	.uni-cropper-dashed-h {
		position: absolute;
		top: 33.33333333%;
		left: 0;
		width: 100%;
		height: 33.33333333%;
		border-top: 1rpx dashed rgba(255, 255, 255, 0.5);
		border-bottom: 1rpx dashed rgba(255, 255, 255, 0.5);
	}
	/* 纵向虚线 */
	
	.uni-cropper-dashed-v {
		position: absolute;
		left: 33.33333333%;
		top: 0;
		width: 33.33333333%;
		height: 100%;
		border-left: 1rpx dashed rgba(255, 255, 255, 0.5);
		border-right: 1rpx dashed rgba(255, 255, 255, 0.5);
	}
	/* 四个方向的线  为了之后的拖动事件*/
	
	.uni-cropper-line-t {
		position: absolute;
		display: block;
		width: 100%;
		background-color: #69f;
		top: 0;
		left: 0;
		height: 1rpx;
		opacity: 0.1;
		cursor: n-resize;
	}
	
	.uni-cropper-line-t::before {
		content: '';
		position: absolute;
		top: 50%;
		right: 0rpx;
		width: 100%;
		-webkit-transform: translate3d(0, -50%, 0);
		transform: translate3d(0, -50%, 0);
		bottom: 0;
		height: 41rpx;
		background: transparent;
		z-index: 11;
	}
	
	.uni-cropper-line-r {
		position: absolute;
		display: block;
		background-color: #69f;
		top: 0;
		right: 0rpx;
		width: 1rpx;
		opacity: 0.1;
		height: 100%;
		cursor: e-resize;
	}
	
	.uni-cropper-line-r::before {
		content: '';
		position: absolute;
		top: 0;
		left: 50%;
		width: 41rpx;
		-webkit-transform: translate3d(-50%, 0, 0);
		transform: translate3d(-50%, 0, 0);
		bottom: 0;
		height: 100%;
		background: transparent;
		z-index: 11;
	}
	
	.uni-cropper-line-b {
		position: absolute;
		display: block;
		width: 100%;
		background-color: #69f;
		bottom: 0;
		left: 0;
		height: 1rpx;
		opacity: 0.1;
		cursor: s-resize;
	}
	
	.uni-cropper-line-b::before {
		content: '';
		position: absolute;
		top: 50%;
		right: 0rpx;
		width: 100%;
		-webkit-transform: translate3d(0, -50%, 0);
		transform: translate3d(0, -50%, 0);
		bottom: 0;
		height: 41rpx;
		background: transparent;
		z-index: 11;
	}
	
	.uni-cropper-line-l {
		position: absolute;
		display: block;
		background-color: #69f;
		top: 0;
		left: 0;
		width: 1rpx;
		opacity: 0.1;
		height: 100%;
		cursor: w-resize;
	}
	
	.uni-cropper-line-l::before {
		content: '';
		position: absolute;
		top: 0;
		left: 50%;
		width: 41rpx;
		-webkit-transform: translate3d(-50%, 0, 0);
		transform: translate3d(-50%, 0, 0);
		bottom: 0;
		height: 100%;
		background: transparent;
		z-index: 11;
	}
	
	.uni-cropper-point {
		width: 5rpx;
		height: 5rpx;
		background-color: #69f;
		opacity: .75;
		position: absolute;
		z-index: 3;
	}
	
	.point-t {
		top: -3rpx;
		left: 50%;
		margin-left: -3rpx;
		cursor: n-resize;
	}
	
	.point-tr {
		top: -3rpx;
		left: 100%;
		margin-left: -3rpx;
		cursor: n-resize;
	}
	
	.point-r {
		top: 50%;
		left: 100%;
		margin-left: -3rpx;
		margin-top: -3rpx;
		cursor: n-resize;
	}
	
	.point-rb {
		left: 100%;
		top: 100%;
		-webkit-transform: translate3d(-50%, -50%, 0);
		transform: translate3d(-50%, -50%, 0);
		cursor: n-resize;
		width: 36rpx;
		height: 36rpx;
		background-color: #69f;
		position: absolute;
		z-index: 1112;
		opacity: 1;
	}
	
	.point-b {
		left: 50%;
		top: 100%;
		margin-left: -3rpx;
		margin-top: -3rpx;
		cursor: n-resize;
	}
	
	.point-bl {
		left: 0%;
		top: 100%;
		margin-left: -3rpx;
		margin-top: -3rpx;
		cursor: n-resize;
	}
	
	.point-l {
		left: 0%;
		top: 50%;
		margin-left: -3rpx;
		margin-top: -3rpx;
		cursor: n-resize;
	}
	
	.point-lt {
		left: 0%;
		top: 0%;
		margin-left: -3rpx;
		margin-top: -3rpx;
		cursor: n-resize;
	}
	/* 裁剪框预览内容 */
	
	.uni-cropper-viewer {
		position: relative;
		width: 100%;
		height: 100%;
		overflow: hidden;
	}
	
	.uni-cropper-viewer image {
		position: absolute;
		z-index: 2;
	}
</style>